Add GraalVM Reachability Metadata and corresponding nativeTest for OpenGauss integration

[linghengqian]

For #29052.

Changes proposed in this pull request:

• Add GraalVM Reachability Metadata and corresponding nativeTest for OpenGauss integration.
• Fixes a bug where MySQLTest incorrectly created a Docker Image instance when the Maven Profile of generateMetadata or nativeTestInShardingSphere was not activated.
• Because there is a bug that needs to be verified on the side of TestContainers, the current NativeTest does not allow running through Podman. Modify the corresponding document.

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